Heart murmur

Heart murmur – Definition

A heart murmur is an abnormal sound made by turbulent blood flow in the heart. It sounds like whooshing or swishing with each heartbeat. Some adults and many children have incidental heart murmurs that are harmless (benign) and are not caused by abnormalities in the heart. At least 30% of children may have an innocent heart murmur at some point during childhood. However, some heart murmurs can signal an underlying heart problem.

Heart murmur – Causes

Benign murmurs are caused by the normal flow of blood through the heart and large vessels near the heart. The murmur may come and go over time. Some things that can increase blood flow and cause a benign heart murmur to be heard include:

Exercise

Pregnancy

Extreme anxiety

Anemia

Fever

Hyperthyroidism

Abnormal heart murmurs can be due to:

Structural abnormalities of the heart valves (most common) — These may be present from birth (congenital). The structural abnormalities may also be acquired later in life due to certain conditions, such as:

Atherosclerosis

Rheumatic fever

Mitral stenosis

Mitral regurgitation

Aortic stenosis

Aortic regurgitation

Tricuspid stenosis

Tricuspid regurgitation

Pulmonary stenosis

Abnormal holes in the structure of the heart persisting after birth:

Septal defects — connection between the heart’s chambers

Patent ductus-arteriosus — connection between the major artery and vein near the heart

Endocarditis — infection of the inner lining of heart valves and chambers (endocardium)

Cardiac myxoma — a benign soft tumor within the heart (rare)

Heart murmur – Risk Factors

Risk factors for normal heart murmurs include:

Age: 3-7 years old

Pregnancy

Risk factors for abnormal heart murmurs include:

Rheumatic fever

Atherosclerosis

High blood pressure

Autoimmune disease

Congenital heart defects or disease

Heart murmur – Symptoms

Benign heart murmurs usually cause no symptoms. Patients with mitral valve prolapse sometimes complain of vague chest discomfort and other symptoms. It remains unclear whether or not the valvular abnormality is causing the symptoms.

Signs and symptoms of abnormal heart murmurs can include:

Rapid breathing or trouble breathing

Blue lips (cyanosis)

Light-headedness

Chest pain

Palpitations (feeling of rapid or irregular heartbeat)

Exercise intolerance

Failure-to-thrive in children

When Should I Call My Doctor?

If you think that you or your child has a heart murmur, you should see the doctor.

Heart murmur – Diagnosis

Most benign heart murmurs are diagnosed during the course of a routine physical exam with a stethoscope. Some abnormal heart murmurs are also discovered this way. Other abnormal heart murmurs are discovered initially by their symptoms.

Tests may include:

Electrocardiogram — a test that records the heart’s electrical activity using electrodes attached to the surface of the chest. This does not diagnose the cause of the murmur but can provide other useful information about the condition of the heart.

Chest x-ray — an x-ray to determine the approximate size and shape of the heart, and the presence of associated lung swelling (pulmonary edema)

Echocardiogram — a test that uses high-frequency sound waves (ultrasound) to examine the size, shape, and motion of the heart

Cardiac catheterization — a tube inserted into the heart through an artery (usually in the groin) to detect problems with the heart’s structure, function, and blood supply

Blood tests — to check for evidence of a recurrent heart attack or other diseases that may affect the heart (eg, kidney disease, infections, autoimmune conditions)

Heart murmur – Treatment

Benign heart murmurs require no treatment. Treatment of other heart murmurs depends on the underlying cause and extent of the problem.

Treatments include:

Medication

Medicines can either treat the cause of the heart abnormality associated with the murmur or help compensate for its dysfunction:

Heart murmur – Prevention

Get prompt testing and treatment for strep throat to prevent rheumatic fever.

Reduce your risk of atherosclerosis to help prevent valvular heart disease in the distant future. To do this:

Eat a healthy diet with plenty of fruits and vegetables.

Get regular exercise.

If you smoke, quit.

If you have high blood pressure or diabetes, follow your treatment plan.

Although not routinely recommended for every type of heart murmur, you may need to take antibiotics before and after some medical or dental procedures that could allow bacteria to enter your bloodstream. Ask your doctor if you need to take preventive antibiotics (eg, if you have a high-risk condition).